Dear Monks,

I have some code that does this:

s/\[\[(\w+)\]\]/$helper->($1)/eg;
[download]

Where $helper is an anonymous function that returns the text to be substituted. This works great with perl 5.6, but breaks in 5.8 with:

panic: sv_pos_b2u: bad byte offset at [...].
[download]

I'm not sure what the problem is, I've also tried:

s/\[\[(\w+)\]\]/@{[$helper->($1)]}/g;
[download]

which fails in the same way. I briefly thought about doing something sort of like:

while (m/\[\[(\w+)\]\]/) {
    my $foo = $helper->($1);
    s/\[\[(\w+)\]\]/$foo/;
}
[download]

But the problem with that (besides it being inefficient) is that m// and s/// seem to use the same pointer to mark where in the string the last search ended--so the substitution changes the *next* occurrence of the pattern, not the one the m// matched.

So I'd like to know:

• Can I reset the pointer to the beginning of the string, so that the s/// will match the same text the m// did?
• Are there any pointers to documentation that explains my problem in more detail? I haven't been able to find anything.
• Anyone have any other suggestions?

I await enlightenment :-)

-Dan

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